Added create and remove static lease and restore leases

lib/screens/settings/dhcp/delete_static_lease_modal.dart

@@ -0,0 +1,44 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+
+class DeleteStaticLeaseModal extends StatelessWidget {
+  final void Function() onConfirm;
+
+  const DeleteStaticLeaseModal({
+    Key? key,
+    required this.onConfirm
+  }) : super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return AlertDialog(
+      title: Column(
+        children: [
+          const Icon(
+            Icons.delete_rounded,
+            size: 26,
+          ),
+          const SizedBox(height: 20),
+          Text(
+            AppLocalizations.of(context)!.deleteStaticLease,
+            textAlign: TextAlign.center,
+          )
+        ],
+      ),
+      content: Text(AppLocalizations.of(context)!.deleteStaticLeaseDescription),
+      actions: [
+        TextButton(
+          onPressed: () => Navigator.pop(context), 
+          child: Text(AppLocalizations.of(context)!.cancel)
+        ),
+        TextButton(
+          onPressed: () {
+            onConfirm();
+            Navigator.pop(context);
+          }, 
+          child: Text(AppLocalizations.of(context)!.confirm)
+        ),
+      ],
+    );
+  }
+}